There are several reasons why you might be getting an "Invalid Password" error message:

• Set your CAPS LOCK key correctly. Passwords are case sensitive (meaning that "PASSWORD," "PaSsWoRd," and "password" are not equivalent), so be sure to keep this in mind when entering your password.
• Sign in with the correct Yahoo! ID. Make sure that you are using the correct Yahoo! ID when signing in to your account. If you have forgotten your Yahoo! ID, you can search for your ID online.

If you're still having problems, please request a new password. After you receive your new password, you can change it.

For more information regarding Yahoo! IDs and passwords, please read this help section.